Sudsing profile is important for a cleaning composition, particularly laundry detergents, where the appropriate volume and speed of suds formation, retention and disappearance in the wash and rinse cycles are considered key benchmarks of performance by the consumers.
Consumers viewed copious suds in the wash as the primary and most desirable signal of cleaning. High suds are especially desirable during hand washing of fabrics, since the consumer can directly feel and touch the suds generated during the wash cycle and will intuitively correlates the high suds volume with the achievement of sufficient fabric cleaning.
Paradoxically, while a large volume of suds is desirable during the wash cycle of fabric cleaning, it is nevertheless undesirable during the rinse cycle. If such high suds are still present during rinse, then the consumers immediately infer from it that there may still be surfactant residue on the fabrics and that the fabrics are not yet “clean”. As a result, the consumers feel the need to rinse the fabrics multiple times in order to make sure that the surfactants are removed as thoroughly as other soils. Because water is often a limited resource, especially in hand washing countries, the excess amount of water consumed by multiple rinses reduces the amount of water available for other possible uses, such as irrigation, drinking, bathing, etc.
Various foam-control or anti-foaming agents have been added to detergent for cleaning compositions to control and reduce the suds volume during the wash. For example, U.S. Pat. No. 8,536,109 (Dow Corning) discloses a foam control composition that contains a silicone anti-foam dispersed in an organopolysiloxane resin, wherein the silicone anti-foam includes an organopolysiloxane, an organosilicon resin, and a hydrophobic filler; U.S. Pat. No. 7,566,750 (Wacker) discloses a defoamer composition containing an organopolysiloxane, filler particles and/or an organopolysiloxane resin, and a very minor amount of added water, which is more effective in reducing the foam or suds volume.
However, the suds control benefit imparted by such foam control or anti-foaming agents may come at the expense of wash suds. Timing for release of the foam control or anti-foam agents is difficult to control. Correspondingly, inopportune release of the foam control or anti-foam agents may lead to significant reduction of the wash suds volume, which will give consumer the impression that the detergent or cleaning composition contains lower surfactant level and is therefore of lower quality/value.
Accordingly, there is a continuing need for better foam control or anti-foaming compositions that can further improve or optimize the sudsing profile of detergent or cleaning compositions, by achieving significant rinse suds reduction but at little or no expense to the wash suds, i.e., minimizing the wash suds reduction.
It would also be advantageous to formulate an improved detergent or cleaning composition that can generate ample suds during the wash cycle to delight the consumers but leaves little or no suds during the rinse cycle to enable a “single rinse” of the fabric for more cost saving and better environmental conservation.